‘Rim joist’ frost and foam insulation
The ‘rim joist’ in my basement was insulated with pieces of roxul placed in stud bays. I wish to seal this area with a couple inches of spray foam and then reinstall the roxul.
Along the gable ends of the house, a sill plate was placed at the top of the concrete foundation. Short studs extend upward from the plate about 8″ to a double plate. Exterior sheathing spans the height between the sill plate and the double plate above, rather than a rim joist made of 2-by stock.
When I removed the roxul from the stud along the gable side of the house I noticed very light frost in some of them. I am wondering if I should be overly concerned about the frost and/or reconsider my plan to spray a couple inches of foam along the rim. If I proceed with spraying, I assume I should let the frosted areas completely dry before proceeding. Correct?
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